Infections of the respiratory tract are very common, especially in infants and small children. For example, in the first year of life, an infant will often experience from three to six such infections. Such infections are usually of bacterial origin and often follow a viral infection such as influenza. Examples of bacterial infections of the respiratory tract include pneumonia, bronchiolitis, sinusitis, pharyngitis, and otitis media.
Acute respiratory infections (ARI) are secondary bacterial infections (as opposed to upper respiratory tract infections). They may lead to middle ear infection, bronchitis, bronchiolitis, pneumonia, sinusitis, pharyngitis, otitis or strep throat. People with chronic lung disease, asthma, diabetes, or a weakened immune system are more likely to develop these complications.
Frequent acute respiratory infections (ARI) are often associated with acute otitis media. This is an infection of the middle ear in which the Eustachian tube connecting the cavity of the middle ear with the external environment via the mouth becomes inflamed and then blocked, trapping bacteria inside the middle ear. In severe cases, the tympanic membrane may burst under pressure allowing the infected liquid to reach the inner ear. This is a potentially dangerous situation which can lead to permanently impaired hearing if left untreated.
Acute otitis media appears to be linked to the activity of pathogenic bacteria commonly found in the indigenous microbiota of the naso-pharyngeal cavity. Quantitatively, the most significant pathogens are Streptococcus pneumoniae (35% of case), untypeable Haemophilus influenzae (30% of cases) and Moraxella catarrhalis (10% of cases).
50% of children will have had a least one episode of acute otitis media in the first year of their life and 35% of children between one and three years of age have recurrent episodes of acute otitis media.
Bronchiolitis is another common illness of the respiratory tract caused by an infection affecting the tiny airways, called the bronchioles that lead to the lungs. As these airways become inflamed, they swell and fill with mucus, making breathing difficult.
Although it is often a mild illness, some infants are at risk of contracting a more severe disease requiring hospitalization. The conditions which increase the risk of severe bronchiolitis include prematurity, prior chronic heart or lung disease, and a weakened immune system due to illness or medications.
Young children who have had bronchiolitis may be more likely to develop asthma later in life, but it is unclear whether the illness causes or triggers asthma, or whether children who eventually develop asthma were simply more prone to developing bronchiolitis as infants.
Bronchiolitis is usually caused by a viral infection, which is in general due to the respiratory syncytial virus (RSV). RSV infections are responsible for more than half of all cases of bronchiolitis and are most widespread in the winter and early spring. Other viruses associated with bronchiolitis include rhinovirus, influenza (flu), and human metapneumovirus.
From the foregoing, it may be seen that there is a need for an effective method for preventing the ARI infections and/or relieving the symptoms of ARI, bronchiolitis and acute otitis media (or otitis) in particular.
Human milk oligosaccharides (HMOs) are, collectively, the third largest solid constituents in human milk, after lactose and fat. HMO usually consists of lactose at the reducing end with a carbohydrate core that often contains a fucose or a sialic acid at the non-reducing end. There are approximately one hundred milk oligosaccharides that have been isolated and characterized, however these represent only a very small portion of the total number remaining to be characterized.
In the past, infant formulae were developed using HMO ingredients, such as fucosylated oligosaccharides, lacto-N-tetraose, lacto-N-neotetraose, or sialylated oligosaccharides, for different purposes.
EP 0 975 235 B1 from Abbott Laboratories describes a synthetic nutritional composition comprising one or more human milk oligosaccharides, wherein the HMOs in the composition are chosen among a group of eight HMOs (3-fucosyllactose, lacto-N-fucopentaose III, lacto-N-fucopentaose II, difucosyllactose, 2′-fucosyllactose, lacto-N-fucopentaose I, lacto-N-neotetraose and lacto-N-fucopentaose V) wherein said composition is intended for cases of normal, healthy infants, children, adults or subjects having specialized needs such as those that accompany certain pathological conditions. This European patent states that, generally speaking, oligosaccharides protect infants from viral and bacterial infections of the respiratory, gastrointestinal and uro-genital tracts.
From the foregoing, it may be seen that there is a need for an effective nutritional composition for preventing acute respiratory infections and/or relieving symptoms of acute respiratory infections, particularly in infants and young children, and which may be conveniently and safely administered.
There is a need to alleviate the symptoms and/or to reduce the severity, frequency, occurrence and/or duration of ARI, in particular otitis or bronchiolitis, in susceptible individuals, especially infants, and more specifically infants presenting a history of such conditions or risk factors.
There is a need for such intervention that reserves the metabolic balance of such fragile individuals and thus is not accompanied by side effects such as the disturbance of the immune system or the change in the inflammation status.
There is a need to improve of the symptoms and to alleviate the conditions often associated of acute respiratory infections, in particular otitis and bronchiolitis, by a non-drug-based intervention that is compatible with fragile individuals like infants or babies.
These conditions can include the effects on sleep quality and/or quantity, pain, hyper or hypo-activity, and/or crying time.